Intelligence in early adulthood and subsequent risk of assault: cohort study of 1,120,998 Swedish men

Whitley, E. , Batty, G.D., Gale, C.R., Deary, I.J., Tynelius, P. and Rasmussen, F. (2010) Intelligence in early adulthood and subsequent risk of assault: cohort study of 1,120,998 Swedish men. Psychosomatic Medicine, 72(4), pp. 390-396. (doi: 10.1097/PSY.0b013e3181d137e9)

Abstract

<p>Objective: To examine the association between low intelligence (IQ) and increased risk of assault. Previous studies have been relatively small, have not adjust for socioeconomic status, and have not examined method-specific assaults.</p> <p>Methods: Cox proportional hazards regression was used to explore IQ associations with assault by any means and by four specific methods in a large prospective cohort of 1,120,988 Swedish men. Study members had IQ measured in early adulthood and were well characterized for socioeconomic status in childhood and adulthood. Men were followed-up for an average of 24 years, and hospital admissions for injury due to assault were recorded.</p> <p>Results: A total of 16,512 (1.5%) men had at least one hospital admission for injury due to assault by any means during follow-up. The most common assault was during a fight (n = 13,144), followed by stabbing (n = 1,211), blunt instrument (b = 352), and firearms assaults (n = 51). After adjusting for confounding variables, lower IQ scores were associated with an elevated risk of hospitalization for assaults by any means (hazard ratio per standard deviation decrease in IQ, 1.51; 95% confidence interval, 1.49, 1.54) and for each of the cause-specific assaults: fight: 1.48 (1.45, 1.51); stabbing: 1.68 (1.58, 1.79); blunt instrument: 1.65 (1.47, 1.85); and firearms: 1.34 (1.00, 1.80). These gradients were stepwise across the full IQ range.</p> <p>Conclusions: Low IQ scores in early adulthood were associated with a subsequently increased risk of assault. A greater understanding of mechanisms underlying these associations may provide opportunities and strategies for prevention.</p>

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Whitley, Dr Elise and Batty, Dr G
• Authors: Whitley, E., Batty, G.D., Gale, C.R., Deary, I.J., Tynelius, P., and Rasmussen, F.
• College/School: College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > MRC/CSO SPHSU; College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > Public Health
• Journal Name: Psychosomatic Medicine
• ISSN: 0033-3174
• ISSN (Online): 1534-7796